如何在WPF ViewModel中使用模型验证规则

public class User
{
    public string Name { get; set; }
}

public class UserViewModel : INotifyPropertyChanged
{
    private User _user;

    public UserViewModel()
    {
        _user = new User();
    }

    public string Name
    {
        get { return _user.Name; }
        set
        {
            if (_user.Name != value)
            {
                _user.Name = value;
                OnPropertyChanged(nameof(Name));
            }
        }
    }

    // INotifyPropertyChanged implementation
    public event PropertyChangedEventHandler PropertyChanged;

    protected virtual void OnPropertyChanged(string propertyName)
    {
        PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
    }
}

public class UserValidator : AbstractValidator<User>
{
    public UserValidator()
    {
        RuleFor(user => user.Name).NotEmpty().WithMessage("姓名不能为空");
    }
}

public class UserViewModel : INotifyPropertyChanged
{
    private User _user;
    private UserValidator _validator;

    public UserViewModel()
    {
        _user = new User();
        _validator = new UserValidator();
    }

    public string Name
    {
        get { return _user.Name; }
        set
        {
            if (_user.Name != value)
            {
                _user.Name = value;
                OnPropertyChanged(nameof(Name));
                Validate();
            }
        }
    }

    public string Error { get; private set; }

    private void Validate()
    {
        var validationResult = _validator.Validate(_user);
        Error = validationResult.IsValid ? null : validationResult.Errors.FirstOrDefault()?.ErrorMessage;
    }

    // INotifyPropertyChanged implementation
    public event PropertyChangedEventHandler PropertyChanged;

    protected virtual void OnPropertyChanged(string propertyName)
    {
        PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
    }
}

<TextBox Text="{Binding Name, UpdateSourceTrigger=PropertyChanged}" />
<TextBlock Text="{Binding Error}" Foreground="Red" />